When a person is extremely sexually attractive. To emphasize exactly how hot a person is, the words over and bridge can be stretched out. Additional expressions derived from this term include "On the bridge" for someone who is decently attractive but not a super-hottie, "Under the Bridge" or "Swimming" for someone who is just a disgusting ugly troll, holding no sexual appeal at all, and "Miles from Water" for someone who just isn't trying.

Nathan: "Holy shit! Did you see that girl!"
Dylan:"Hell yeah! Over the Bridge!"
or
Miles: "Look at that warthog!"
Zach:"Bitch is swimming, bro. She's so far under the bridge she hit seafloor."